Genome-Wide Identification and Analysis of the Fatty Acid Export Family Revealed the Role of GmFAX8 in Improving Soybean Oil Accumulation

Fatty acid transporters (FAXs) play an important role in fatty acid synthesis by facilitating transport fatty acids from the plastid to the endoplasmic reticulum. This process is essential for providing precursor substances necessary for triglycerides (TAGs). Although <i>FAX</i> genes have been identified in variety of plant species, the identification and molecular functions of the <i>GmFAX</i> gene members in soybean are still unclear. In this study, soybean <i>FAX</i> genes were identified through the utilization of the Phytozome (v13) and NCBI online websites. Subsequently, phylogenetic trees, expression patterns, gene structures, and qRT-PCR were analyzed. A total of eight <i>GmFAX</i> members were identified at the whole genome level, and further phylogenetic analysis revealed that these members can be categorized into four subfamilies. In addition, all members of <i>GmFAX</i> contain a highly conserved domain Tmemb_14. Through qRT-PCR analysis, it was found that the expression level of the <i>GmFAX8</i> gene is relatively high in leaves and stems. Further investigation revealed that the total fatty acid content in hairy roots overexpressing the <i>GmFAX8</i> gene was significantly greater than that observed in the control strain. The results presented above suggest that the <i>GmFAX8</i> gene may play an important role in the accumulation of oil within soybeans.